PORTFS(4)                                               PORTFS(4)

     NAME
          portfs, sendfs, youps - we deliver events and messages for
          Plan B

     SYNOPSIS
          portfs [ -abcAD] ] [ -m mnt ] [ -s srv ] [ -n addr ] [ -V
          vol ]

          sendfs [ -d ] [ -p portfile ]

          youps

     DESCRIPTION
          The youps program suite (pronounced you-p-s) receives, exam-
          ines, rewrites, and dispatches plumb(6) messages to ports
          provided by machines owned by the user.  Its behaviour is
          similar to plumber(4), when used in a centralized setting.

          Portfs implements a file system that provides message ports.
          A port can be created by creating a file. Data written to a
          port is delivered to all processes reading from the port.
          Data uses to be plumb messages, but it may be any other
          thing. Once a port has ben read, when all readers of a port
          close the port, the port is removed. By default, portfs
          mounts itself at /devs/ports and listens for network clients
          at tcp!*!11002.  Options are similar to those of most file
          servers, as described in planb(4).

          Sendfs delivers events to ports. The program services are
          mounted on the directory /mnt/plumb and consists of two
          pre-defined files: send.  and rules.

          Programs use write (see read(2)) to deliver messages to the
          send file, and sendfs decides, looking at its configuration,
          to which port the message should be sent.  The behaviour and
          configuration is like in plumber(4). Beware that commands
          used within a plumb rule should supply the -p option to any
          plumb (1) command issued within the rule. Otherwise, plumb
          will not be able to deliver the message because there is no
          send file in the file system as seen by the command (That
          file is implemented by sendfs only as a front-end for the
          user).

          The file rules behaves like in plumber(4) and permits con-
          figuration of the service.

          youps is a convenience script that starts the service by
          running portfs and sendfs after mounting a union of all user
          ports at /mnt/plumb.

     PORTFS(4)                                               PORTFS(4)

     FILES
          /usr/$user/lib/plumbing  default rules file
          /sys/lib/plumb           directory to search for files in
                                   include statements.
          /mnt/plumb               mount point for the send file and
                                   the union of all ports. The ports
                                   of the local machine are mounted
                                   above those of others.
          /devs/ports              ports serviced by the local
                                   machine.

     SOURCE
          /sys/src/cmd/youps

     SEE ALSO
          plumber(4), plumb(1), plumb(2), plumb(6)

     BUGS
          The delivery of messages across the network is not secured.